EP1768575B1

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Info

Publication number: EP1768575B1
Application number: EP05761687.2A
Authority: EP
Inventors: Alison Lutterman; Paul T. Rothstein; David E. Francischelli; Roderick E. Briscoe; Leonard H. Leuer; Daniel C. Haeg; Tomas P. Daigle; Philip C. Falkner; Eduardo N. Warman; Douglas A. Hettrick; Marie T. Steinbrink; David J. S. Kim; Mark T. Stewart; Steven C. Christian; Christopher P. Olig
Original assignee: Medtronic Inc
Current assignee: Medtronic Inc
Priority date: 2004-06-18
Filing date: 2005-06-16
Publication date: 2019-01-16
Anticipated expiration: 2025-06-16
Also published as: WO2006009729A3; US20060020271A1; EP1768575A2; EP1768575A4; WO2006009729A2

Description

FIELD OF THE INVENTION

The invention relates to devices for occlusion or ligation of an atrial appendage.
US 6 152 936 A describes a surgical loop delivery device.US 2 840 082 A describes an elastic band expanding device.DE 35 27 762 A describes a surgical instrument for ligating piles or the like.US 2 561 286 A describes a device for applying emasculating rings.US 3 454 011 A describes sutures and prosthetic patches.WO 00/74745 A describes a drug releasing elastic band and method.US 2002/0049457 A1 describes methods and apparatus for transpericardial left atrial appendage closure.

BACKGROUND OF THE INVENTION

Embolic stroke is the nation's third leading killer for adults. Embolic stroke is also a major cause of disability. The most common cause of embolic stroke is thrombus formation in the left appendage on the atrium. In almost all atrial fibrillation (AF) patients suffering from embolic stroke, a thrombus clot forms in the appendage of the left atrium.
The primary therapy for the prevention of stroke in AF patients is the administration of oral anticoagulants. Although somewhat effective, there are numerous side effects, including bleeding and lifestyle compromises. Pharmacological therapies (such as Warfarin®) are not well tolerated by patients. The introduction of biomaterials into the left atrial appendage has resulted in the biomaterials eventually breaking down resulting in clot formation. The left atrial appendage has been removed by others via open chest and thoroscopic surgical approaches. Such a procedure is described by Johnson in United States Patent Number5,306,234 entitled "Method for Closing an Atrial Appendage." The '234 patent discloses a method for grasping the left atrial appendage and manipulating it into position in order to sever the tissue and remove the appendage. The wound on the heart is then sewn or clamped shut.
Appriva Medical, Inc. has been developing concepts for occluding the left atrial appendage from a percutaneous endocardial approach. In United States Patent Number6,152,144 entitled "Method and Device for Left Atrial Appendage Occlusion" assigned to Appriva Medical, a device and method for isolating the left atrial appendage from the inside of the heart is disclosed. A barrier or other device is anchored in the chamber of the left atrial appendage to prevent the passage of blood into and out of the chamber and thereby prevent clot formation. However, any foreign device left in the chamber of the heart is a potential thrombosis-generating site. In addition, biomaterials are known to eventually break down and result in clotting.
Some surgeons will remove or oversew the left atrial appendage as a concomitant procedure during other cardiac surgery. This is done under general anesthesia and may result in additional trauma to the patient.
While endoscopic or percutaneous approaches reduce the invasiveness of the surgical procedure, the above-described approaches have inherent limitations. Surgical removal of the left atrial appendage is very invasive and often results in loss of atrial hormones, such as atrial natriuretic peptide (ANP), and significant bleeding. In United States Patent Number6,666,861 issued to Grabekand entitled "Atrial Remodeling Device and Method," a method is disclosed for applying a suture lasso placed endoscopically around the left atrial appendage to isolate it from the atrium. The '861 patent describes using either wet cauterization to remove the tissue or leaving the isolated appendage in place.
Endoscopic stapling devices, suture loops tied to the base of the appendage, and clips pinching the appendage from the outside surface to the base to close the appendage are used by physicians to isolate and remove the left atrial appendage. In United States Patent Number6,488,689 issued to Kaplanand entitled "Methods and Apparatus for Transpericardial Left Atrial Appendage Closure," a method and apparatus to close the left atrial appendage is disclosed. The '689 patent describes using a grasper and a closing loop or clip applied to the outside of the left atrial appendage. The clip is applied extending toward the chamber of the atrial appendage and extending over the outside edge of the appendage. The clips of the '689 patent are a U-shaped metal clip, having a spring tendency to hold its shape, being deformed to open while positioned to extend over the tissue, before the clip is allowed to return to its resting shape, having the tissue pinched between the ends of the clip.

SUMMARY OF THE INVENTION

Some embodiments of the invention provide a system for occluding a left atrial appendage of a patient. Some embodiments of the system can include a ring occluder that can be positioned around the left atrial appendage and a ring applicator to position the ring occluder with respect to the left atrial appendage. The ring applicator can include a ring spreader with a spreader hinge coupled to an upper spreader jaw and a lower spreader jaw. The ring occluder can be coupled between the lower spreader jaw and the upper spreader jaw. The spreader hinge can move between an open position in which the ring occluder has a first diameter and a closed position in which the ring occluder has a second diameter, the first diameter being larger than the second diameter.
To aid in the understanding of the invention, a clip occluder that can be positioned around the left atrial appendage is hereby disclosed. The clip occluder can include a clip hinge coupled to an upper clip jaw and a lower clip jaw. The clip occluder can include a clip lock. A clip applicator can position the clip occluder with respect to the left atrial appendage. The clip applicator can include a clip actuator coupled to the clip occluder by an actuator suture. The actuator suture can control a distance between the upper clip jaw and the lower clip jaw. The clip applicator can be removably coupled to the clip occluder with a retention suture.
In some embodiments of the invention, a ring applicator can include a shaft having a handle on a proximal end and a distal end, and a lumen extending from the handle to the distal end of the shaft, an actuator coupled to the handle, and a ring spreader assembly on the distal end of the shaft, the ring spreader assembly having a plurality of ring expanding members. A ring occluder can be releasably attached to the plurality of ring expanding members. The ring occluder can be stretched to an open position by the actuator to allow the ring occluder to be manipulated over tissue to be occluded.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of an exemplary left atrial appendage occlusion device placed around the left atrium before compressing the tissue of the left atrial appendage.
FIG. 2 is a schematic illustration of the left atrial appendage occlusion device ofFIG. 1 clamped around the left atrial appendage.
FIG. 3 is a perspective view of a ring occluder on a patient's heart isolating the left atrial appendage.
FIG. 4 is a perspective view of a variety of ring occluders illustrating the relative size differences that are available.
FIG. 5 is a perspective view of a ring occluder applicator according to one embodiment of the invention.
FIG. 6 is a perspective view of an applicator head of the ring occluder applicator ofFIG. 5.
FIG. 7 is a perspective view of the handle mechanism of the ring occluder applicator ofFIG. 5.
FIG. 7A is a perspective view of the ring occluder applicator inFIG. 5 with a ring occluder attached.
FIG. 8 is a perspective view of the ring occluder applicator ofFIG. 5 with a ring occluder attached and in a stretched-open position.
FIG. 9A is a side view of the ring occluder applicator ofFIG. 7 with the ring occluder in a relaxed position.
FIG. 9B is a side view of the ring occluder applicator inFIG. 7 with the ring occluder in a partially-stretched open position.
FIG. 9C is a side view of the ring occluder applicator ofFIG. 7 with the ring occluder in a stretched-open position.
FIG. 10 is a cross-sectional schematic illustration of an exemplary left atrial appendage occlusion device, before being clamped around the left atrial appendage.
FIG. 11 is a cross-sectional schematic illustration of the occlusion device ofFIG. 10, after being clamped around the left atrial appendage.
FIG. 12 is a perspective view of the occlusion device ofFIG. 10 applied to a patent's heart.
FIG. 12A is an end view of the occlusion device ofFIG. 10 applied to a patient's heart.
FIG. 13 is a perspective view of an exemplary clip applicator
FIG. 14 is a perspective view of an applicator head of the clip applicator ofFIG. 13.
FIG. 15 is a perspective view of the clip applicator ofFIG.14 with the clip attached and in a spring-biased open position.
FIG. 16 is a perspective view of the clip applicator ofFIG. 14 with the clip attached and in an insert position.
FIG. 17 is a perspective view of the clip applicator ofFIG. 14 with the clip detached and in a locked position.
FIG. 18 is a cross-sectional schematic illustration of an exemplary left atrial appendage occlusion device, before compressing tissue of the left atrial appendage.
FIG. 19 is a cross-sectional schematic illustration of the occlusion device ofFIG. 18, after being clamped around the left atrial appendage.
FIG. 20 is a cross-sectional schematic illustration of the occlusion device ofFIG. 20 with one or more ratcheting arms removed.
FIG. 21 is a cross-sectional schematic illustration of an exemplary left atrial appendage occlusion device, before compressing tissue of the left atrial appendage.
FIG. 22 is a cross-sectional schematic illustration of the occlusion deviceFIG. 22 after compressing tissue of the left atrial appendage.
FIG. 23 is a perspective view of an exemplary applicator for inserting and applying a left atrial appendage occluder.
FIG. 24 is an exploded perspective view of the occluder ofFIG. 23.
FIG. 25 is a perspective view of the occluder ofFIG. 24 after assembly.
FIG. 26 is a perspective view of the occluder ofFIG. 25 being mounted on the applicator ofFIG. 23.
FIG. 27 is a perspective view of the occluder fully mounted on the applicator ofFIG. 23.
FIG. 28 is a perspective view of the occluder compressed on the applicator ofFIG. 23.
FIG. 29 is a perspective view of the occluder compressed and disconnected from the applicator ofFIG. 23.
FIG. 30 is a perspective view of one exemplary device.
FIG. 31 is a partial perspective view of the device ofFIG. 30 in use.
FIG. 32 is a schematic illustration of an exemplary occlusion device positioned around the left atrial appendage.
FIG. 33 is a schematic illustration of the occlusion device ofFIG. 32 clamped around the left atrial appendage.
FIG. 34 is a perspective view of an exemplary adjustable band occluder.
FIG. 35 is a perspective view of a deployed percutaneous left atrial appendage transcatheter occlusion (PLAATO) device.
FIGS. 36A-E are perspective views of an endoloop left atrial appendage ligation procedure.
FIGS. 37A-E are side and perspective views of an atrial septal defect repair device.
FIG. 38 is a schematic cross-sectional representation of a heart and a chest wall.
FIG. 39 is a side view of an exemplary device passed through a port placed between the ribs.
FIG. 40 is a side view of the device ofFIG. 39 advanced toward the left atrial appendage.
FIG. 41 is a side view of the device ofFIG. 39 including a suction cup or grasper probe being advanced through portal tube.
FIG. 42 is a side view of the device ofFIG. 41 with the suction cup or grasper probe attached to an end of the left atrial appendage.
FIG. 43 is a side view the device ofFIG. 41 with cinch-ring support arms expanded and the left atrial appendage pulled toward a portal tube.
FIG. 44 is a side view of the device ofFIG. 41 with the cinch-ring support arms advanced over the left atrial appendage.
FIG. 45 is a side view of the device ofFIG. 41 with the cinch-ring support arms positioned over a mid to proximal left atrial appendage.
FIG. 46 is a side view of the device ofFIG. 41 with the cinch-ring support arms allowed to contract over the left atrial appendage and occlude a lumen of the left atrial appendage.
FIG. 47 is a side view of the device ofFIG. 41 with the suction cup or grasper probe removed from the portal tube.
FIG. 48 is a side view of a dilator/sheath assembly advanced through the portal tube.
FIG. 49 is a side view of the dilator/sheath assembly ofFIG. 48 with a needle or sharp wire advanced through a lumen of the dilator to puncture into the left atrial appendage lumen.
FIG. 50 is a side view of the dilator ofFIG. 49 advanced into the lumen of left atrial appendage and the needle retracted.
FIG. 51 is a side view of the dilator ofFIG. 49 with the sheath advanced over the dilator into left atrial appendage lumen.
FIG. 52 is a side view of the dilator ofFIG. 51 with the left atrial appendage lumen being aspirated of blood and flushed with heparinized saline to prevent thrombus formation.
FIG. 53 is a side view of the dilator ofFIG. 51 with the left atrial appendage being filled with heparinized saline as blood and air are removed.
FIG. 54 is a side view of the dilator ofFIG. 51 being advanced past the cinch ring and into the left atrium.
FIG. 55 is a side view of the sheath ofFIG. 51 being advanced over the dilator past the cinch ring and into the left atrium.
FIG. 56 is a side view of the sheath ofFIG. 51 with the dilator removed.
FIG. 57 is a side view the sheath ofFIG. 56 with therapeutic implements being advanced into the left atrium.
FIG. 58 is a side view of a balloon ablation device according to one embodiment of the invention at the right inferior pulmonary vein ostium.
FIG. 59 is a side view of the balloon ablation device ofFIG. 58 at the left superior pulmonary vein ostium.
FIG. 60 is a side view of an exemplary encircling ablation device approaching the left superior pulmonary vein ostium.
FIG. 61 is a side view of the encircling ablation device ofFIG. 60 placed around the left superior pulmonary vein ostium.
FIG. 62 is a side view of an exemplary left atrial de-bulking spiral ablation device placed against the posterior left atrium.
FIG. 63 is a side view of an exemplary high intensity focused ultrasound ablation device creating a lesion over the left atrial isthmus.
FIG. 64 is a side view of an exemplary PFO or ASD closure device being deployed in the fossa ovalis of the inter-atrial septum.
FIG. 65 is a side view of an exemplary linear ablation device forming connecting lesions between pulmonary veins.
FIG. 66 is a side view of an exemplary elastic cinch ring allowed to constrict down around the base of the left atrial appendage.
FIG. 67 is a side view of the elastic cinch ring ofFIG. 66 immediately following the procedure.
FIG. 68 is a side view of the elastic cinch ring ofFIG. 66 after approximately 12 weeks.

DETAILED DESCRIPTION

FIG. 1 illustrates an outline of theatrium 10 of the heart with the leftatrial appendage 12 protruding therefrom.FIG. 1 also illustrates anoccluder 14 forming aring 16 that is placed in a position to surround the leftatrial appendage 12 adjacent to a leftatrial appendage base 18, where the leftatrial appendage 12 is attached to theheart 20. Thering 16 can be constructed of an elastic material to allow it to be stretched into an open position, as shown inFIG. 1. Thering 16 can be allowed to return to a closed position, as shown inFIG. 2, to bear against the tissue of the leftatrial appendage 12 in order to close off any interior connection between theatrium 10 and the leftatrial appendage 12.
FIG. 3 illustrates thering 16 attached to a patient'sheart 20 to isolate the leftatrial appendage 12 from theatrium 10. The material of thering 16 can be biocompatible to allow thering 16 to be left on theheart 20 permanently.
FIG. 4 illustrates different relative sizes ofrings 16 that can be used to accommodate different anatomy requirements of the patient. Thering 16 can be manufactured with radio opaque qualities, such asmicro-sized glass beads 26 molded into the material of thering 16. Alternatively, thering 16 can be made radio opaque by the addition of glass ormetallic fibers 28 in the material of thering 16. Thering 16 can be entirely biocompatible to allow for use for the life of the patient. Thering 16 can have size variations in its inner diameter 30 along acontact surface 32. Thering 16 can also have different cross-sectional shapes, such as oval, rectangular, square, etc.
To apply thering 16 to a patient, aring applicator 34, as shown inFIG. 5, can be used. Thering applicator 34 can include ashaft 36 with ahandle 38 on a proximal end and aring spreader 40 on a distal end. Thering spreader 40 can include anupper spreader jaw 42 and alower spreader jaw 44, each connected to aspreader hinge 46. Ajaw actuator 48 on thehandle 38 can include aknob 50.
In some embodiments according to the invention, thespreader hinge 46 includes a four-bar assembly 52 for use in moving theupper spreader jaw 42 and thelower spreader jaw 44 substantially in parallel. The four-bar assembly 52 can include a firstdistal link 54 and a seconddistal link 56, as shown inFIG. 6. The firstdistal link 54 can include a distal end pivotally attached to theupper spreader jaw 42 at a topdistal pivot 58. The seconddistal link 56 can include a distal end pivotally attached to thelower spreader jaw 44 at a lowerdistal pivot 60. The firstdistal link 54 can include a proximal end pivotally attached to theshaft 36 and to a proximal end of the seconddistal link 56 at adistal shaft pivot 57. As a result, the firstdistal link 54 can be pivotally linked to the seconddistal link 56.
Thering spreader 40 can be moved from a relaxed closed position (as shown inFIG. 9A) having theupper spreader jaw 42 in close proximity to thelower spreader jaw 44 to an open position (as shown inFIGS. 8, 9B, and 9C) by thejaw actuator 48. In the open position, theupper spreader jaw 42 can be spaced from thelower spreader jaw 44 by a larger distance than in the closed position.
In some embodiments, as shown inFIG. 6, thering 16 can be removably attached to thering spreader 40 by one or more sutures tied between thehandle 38 and thering 16. In one embodiment, thering 16 can be tied on the front, back, top, and bottom to uniformly open thering 16 for application to a tissue appendage. A front suture 66 and anupper suture 68 can be attached to thejaw actuator 48 and can loop inside theshaft 36 to theupper spreader jaw 42 and around thering 16 at spaced intervals. Aproximal suture 70 and alower suture 72 can be similarly attached to thejaw actuator 48 and can extend inside theshaft 36 to thelower spreader jaw 44 and around thering 16 at spaced intervals.
As shown inFIG. 6, theupper spreader jaw 42 can include afirst feed slot 74 having a firstdistal aperture 75 extending through theupper jaw 42 and a firstupper aperture 79 extending through theupper jaw 42. The firstupper aperture 79 can be disposed between the firstdistal aperture 75 and thespreader hinge 46. Theupper spreader jaw 42 can include areturn slot 76 parallel to thefirst feed slot 74. Thereturn slot 76 can include a seconddistal aperture 77 in proximity to the firstdistal aperture 75 and a secondupper aperture 81 in proximity to the firstupper aperture 79. In some embodiments, the first and secondupper apertures 79 and 81 can both extend through theupper jaw 42.
As shown inFIG. 7A, thelower spreader jaw 44 can include a similar configuration to theupper spreader jaw 42. Thelower spreader jaw 44 can include asecond feed slot 65 with a firstlower aperture 67 and a firstproximal aperture 69. The firstproximal aperture 69 can be disposed between the firstlower aperture 67 and thespreader hinge 46. Asecond return slot 71 can be formed on thelower spreader jaw 44 substantially parallel to thesecond feed slot 65. Thesecond return slot 71 can include a secondlower aperture 73 in proximity to a firstlower aperture 67 and a secondproximal aperture 53 in proximity to the firstproximal aperture 69. The secondproximal aperture 53 can be disposed between thespreader hinge 46 and the secondlower aperture 73.
Thefeed slots 65, 74 can be used to direct the sutures attached at thehandle 38 to thejaw actuator 48. Thesutures 66, 68, 70, 72 can be directed along thespreader jaws 42, 44 and directed to pass through thespreader jaws 42, 44 at theapertures 67, 69, 75, 79. The sutures can 66, 68, 70, 72 then loop around thering 16 at predefined locations. Thesutures 44, 42 can also pass through theapertures 53, 73, 79, 81 and along thereturn slots 71, 76 to return through a lumen to attach to thejaw actuator 48. The front suture 66 can have a first end attached to thejaw actuator 48. The front suture 66 can extend through thehandle 38, along thefirst feed slot 74, through the firstdistal aperture 75, and around thering 16 in a single loop defining the front portion of thering 16. The front suture 66 can also extend back through the seconddistal aperture 77, along thefirst return slot 76, and through thehandle 38 to a second end connected to thejaw actuator 48. Likewise, theupper suture 68 can extend through thehandle 38, along thefirst feed slot 74, through the firstupper aperture 79, and around thering 16 in a single loop defining the upper portion of thering 16. Theupper suture 68 can also extend back through the secondupper aperture 81, along thefirst return slot 76, and through thehandle 38 to a second end connected to thejaw actuator 48.
Thelower suture 72 can have a first end attached to thejaw actuator 48. Thelower suture 72 can extend through thehandle 38, along thesecond feed slot 65, through the firstlower aperture 67, and around thering 16 in a single loop defining the lower portion of thering 16. Thelower suture 72 can also extend back through the secondlower aperture 73, along thesecond return slot 71, and through thehandle 38 to a second end connected to thejaw actuator 48. Likewise, theproximal suture 70 can extend through thehandle 38, along thesecond feed slot 65, through the firstproximal aperture 69, and around thering 16 in a single loop defining the proximal portion of thering 16. Theproximal suture 70 can also extend back through the secondproximal aperture 53, along thesecond return slot 71, and through thehandle 38 to a second end connected to thejaw actuator 48.
FIG. 7 illustrates atorque screw 82 having ahex end 84 channeled in thehandle 38 and attached to thejaw actuator 48. When theknob 50 is rotated, thetorque screw 82 can rotatably traverse to move thehex end 84 in thehandle 38 toward thering spreader 40 or toward theknob 50, depending on which direction theknob 50 is rotated. Thesutures 66, 68, 70, 72 can be attached to thehex end 84 using knots and can extend to loop around thering 16 in thering spreader 40. As theknob 50 is turned to traverse thehex end 84 away from thering spreader 40, thesutures 66, 68, 70, 72 can tighten to bear against thering 16 and thespreader jaws 42, 44 in order to overcome the elasticity of thering 16 and move thespreader jaws 42, 44 to the open position, as shown inFIGS. 8 and 9C. Thespreader jaws 42, 44 can be guided in a substantially parallel path by the four-bar assembly 52 in order to stretch thering 16 to the open position. In some embodiments, the hex end and thetorque screw 82 are replaced by a linear trigger grip. By squeezing the grip handle, the spreader jaws are spread as described above.
In some embodiments, as shown inFIGS. 9A-9C, thespreader hinge 46 can include a topproximal link 86 and a lowerproximal link 88. The topproximal link 86 can include a first end pivotally attached to theshaft 36 and a second end pivotally connected to theupper spreader jaw 42. The lowerproximal link 88 can include a first end pivotally connected to theshaft 36 and a second end pivotally connected to thelower spreader jaw 44. Theproximal links 86, 88 can function with thedistal links 54, 56 to move theupper spreader jaw 42 in a substantially parallel relationship with respect to thelower spreader jaw 44.
Thesutures 66, 68, 70, 72 can act as a retainer to hold thering 16 in thering spreader 40. Thesutures 66, 68, 70, 72 can also act as a portion of thejaw actuator 48 by pulling thering spreader 40 toward thehandle 38 to force thespreader hinge 46 to pivot at the four-bar assembly 52, causing thespreader jaws 42, 44 to spread away from one other and stretching thering 16 open. Thesutures 66, 68, 70, 72 can open thering 16 into a substantially rectangular shape as shown inFig. 9C.
As shown inFIG. 10, a leftatrial appendage chamber 94 can be positioned within a lockingclip 96 in an open position.FIG. 11 illustrates thechamber 94 compressed by the lockingclip 96 in the closed position. The lockingclip 96 can include alower clip jaw 118 made of an elastic material and anupper clip jaw 124 connected to thelower clip law 118 at aclip hinge 122. The lockingclip 96 can be formed from a single piece of elastic material 120 and can define theclip hinge 122 integrally with thelower clip jaw 118 andupper clip jaw 124. The lockingclip 96 can also include a clip lock 126 (e.g., such as a clip barb 128) on theupper clip jaw 124, that is adapted to engage thelower clip jaw 118 at alock receiver 130 to substantially permanently affix theupper clip jaw 124 to thelower clip jaw 118.FIGS. 12 and 12A illustrate an application of the lockingclip 96 on a patient's heart.
FIG. 13 illustrates anexemplary clip applicator 98 for delivering alocking clip 96 into a patient through an incision in a closed-chest routine. Theclip applicator 98 can include ashaft 36 having ahandle 38 on a proximal end, aclip actuator 108 on thehandle 38, and alocking clip 96 coupled to a distal end.
Theclip actuator 108 can be used to move thelocking clip 96 from an open, unlocked position to a closed, locked position. Theclip actuator 108 can include anactuator suture 110 having a first end attached to thehandle 38 and extending through a lumen 112 (as shown inFIG. 14) in thehandle 38. Theactuator suture 110 can engage thelocking clip 96 through a first feed aperture 119 in thelower jaw 118 and can extend through afirst actuator aperture 125 in theupper clip jaw 124 of the lockingclip 96. Theactuator suture 110 can loop over theupper clip jaw 124 and can pass through asecond actuator aperture 123 in theupper clip jaw 124. Theactuator suture 110 can also extend through asecond feed aperture 117 in thelower jaw 118 and back through thehandle 38 to a second end attached to theclip actuator 108. Alternatively, theactuator suture 110 can be looped outside thehandle 38, so that the operator can pull theactuator suture 110 manually to draw theupper clip jaw 124 to engage thelower clip jaw 118 when the lockingclip 96 is in position to engage the leftatrial appendage 12.
The first feed aperture 119 can be positioned through thelower clip jaw 118 to allow theactuator suture 110 to pass through thelower clip jaw 118 to theupper clip jaw 124. Theupper clip jaw 124 can include the first andsecond actuator apertures 125, 123 that can allow theactuator suture 110 to loop around theupper clip jaw 124, while retaining a position near theclip lock 126 on theupper clip jaw 124. Theclip actuator 108 can be a movable actuator, similar to the torque screw assembly on the ring applicator shown inFIGS. 7 and8, or alternatively, a thumb slide or lever. Theclip actuator 108 can pull theactuator suture 110 to engage thelocking clip 96 by pulling theupper clip jaw 124 into engagement with thelower clip jaw 118 at theclip lock 126. Theactuator suture 110 can include a first end coupled to theclip actuator 108. The first end can extend through thelumen 112 passing through thelower jaw 118 to loop around theupper clip jaw 124 and back through thelower clip jaw 118 to terminate at thehandle 38. In this manner, theclip actuator 108 can bear against theactuator suture 110 to pull on the open end of theupper clip jaw 124 and to overcome the spring tenancy of theclip hinge 122 in order to draw theupper clip jaw 124 into a locking engagement with thelower clip jaw 118.
Thelower clip jaw 118 can include anengagement connection 121 to releasably connect thelocking clip 96 to theclip applicator 98 with a retention suture 111 (as shown inFIG. 14). The retention suture 111 can removably attach thelocking clip 96 to theclip applicator 98. The retention suture 111 can include a first end coupled to thehandle 38. The first end can extend from thehandle 38 to thelocking clip 96 to releasably engage thelower clip jaw 118. As shown inFIG.14, the retention suture 111 can loop into anengagement portion 121 of thelower clip jaw 118 so that the retention suture 111 may be cut at one end. The retention suture 111 can be cut at thehandle 38 to draw the retention suture 111 out of the patient and remove theclip applicator 98, while leaving the lockingclip 96 attached to the loweratrial appendage 12. As shown inFIG. 15, theengagement connection 121 can include an aperture in thelower clip jaw 118, adjacent theclip lock 126, that can allow the retention suture 111 to pass into and around a portion of thelower clip jaw 118 and back to thehandle 38.
As shown inFIGS. 14-17, aclip stop 114 and twoalignment pins 116 can be attached to a distal end of thehandle 38. Thelower clip jaw 118 can include one or more receivers (not shown) to receive the alignment pins 116 in order to hold thelocking clip 96 in alignment with theshaft 36 and to prevent rotation of the lockingclip 96 with respect to theshaft 36. Theclip stop 114 can include a retractable element in theshaft 36 that can extend out to a position between thelower clip jaw 118 and theupper clip jaw 124. Theclip stop 114 can extend out to engage thelocking clip 96 as theclip applicator 98 and thelocking clip 96 are passed through a lumen, tube, or endoscope, while the operator is inserting the lockingclip 96 into a patient, in order to prevent thelocking clip 96 from inadvertently locking. After insertion through the lumen, theclip hinge 122 can bear against theclip jaws 118, 124 to open the lockingclip 96 for positioning around the base of the leftatrial appendage 12 or other target tissue, and the clip stop 114 can be retracted into theshaft 36.
FIG. 16 illustrates theclip 96 in an insertion position in which theclip stop 114 is removably engaged between theupper clip jaw 124 and thelower clip jaw 118. The insertion position can help prevent theclip lock 126 from engaging asclip applicator 98 and thelocking clip 96 are passed into a patient's chest through an incision (possibly in a cannula or endoscope). Theclip actuator 108 can be used to pull theactuator suture 110 to move the clip stop 114 into theshaft 36 away from theclip jaws 118, 124. Theclip actuator 108 can bring theclip jaws 118, 124 into a position to lock theclip lock 126 and to hold thelocking clip 96 in a locking position, as shown inFIG. 16.
As shown inFIG.17, the lockingclip 96 can be disengaged from theclip applicator 98 by cutting the retention suture 111 at thehandle 38 and drawing the retention suture 111 out of theclip applicator 98. Likewise, theactuator suture 110 can be released from theclip actuator 108, can be cut, and can be pulled out of the patient and from theclip applicator 98. The locked lockingclip 96 can releasably slide off of the alignment pins 116 and can remain attached to the leftatrial appendage 12 when theclip applicator 98 is removed.
FIGS. 18-20 illustrate an exemplary occluder including a clamp with afirst pressure plate 152 and asecond pressure plate 154. The first andsecond pressure plates 152, 154 can each have one or more end holes 151. A ratcheting mechanism can includeteeth 155 onconnector rods 153 and areceiver 157 for receiving the connectingrod 153 and engaging theteeth 155 to substantially permanently hold theplates 152, 154 in spaced relation to one other in order to isolate the chamber of the leftatrial appendage 12. As shown inFIG. 20, thereceivers 157 can be positioned onto theconnector rods 153 extending from thesecond pressure plate 154. Thereceivers 157 can bear against thefirst pressure plate 152 to hold theplates 152, 154 in a predefined spaced relation. As shown inFIG. 21, the ends of theconnector rods 153 extending from thereceivers 157 can be clipped off after the desired claming is achieved.
FIGS. 21-22 illustrate one exemplary occluder in which thepressure plates 152, 154 can be configured with atie channel 156 passing through eachplate 152, 154 from one end to another. Atie 158 can be passed through thetie channels 156 to connect the first andsecond plates 152, 154 together. Theplates 152, 154 can be positioned to clamp down on the base of the leftatrial appendage 12 to close off the leftatrial appendage chamber 94.
FIGS. 23-29 illustrate oneexemplary loop clip 174 and aloop clip applicator 172 for engaging the left atrial appendage at its base in order to close the chamber of the left atrial appendage. Theloop clip 174 can include alower clip jaw 176 and aloop 178. Theloop 178 can include afixed end 187 attached to thelower clip jaw 176 andteeth 182 that extend to aslidable end 185. Theloop 178 can engage thelower clip jaw 176 at aclip lock 183 to substantially permanently clamp by bearing against tissue trapped between theloop 178 and thelower clip jaw 176.
FIG. 26 illustrates anactuator attachment 180 that can include a retention suture 111 extending from thehandle 38 to anengagement portion 177 on theloop clip 174. Theengagement portion 177 can include an aperture through theloop clip 174 to allow the retention suture 111 to extend from thehandle 38, through theshaft 36 around the engagement portion, and back to thehandle 38. The retention suture 111 can releasably retain theloop clip 174 on theloop clip applicator 172, until theloop clip 174 is secured around the left atrial appendage. The retention suture 111 can be cut at one end and drawn out of the patient to leave theloop clip 174 engaged.
FIG. 24 illustrates anactuator suture 110 attached to theslidable end 185 of theloop clip 174. Theactuator suture 110 can be removably attached to theslidable end 185 of theloop 178 by looping through anactuator aperture 180. Thefixed end 187 of theloop 178 can be attached to thelower clip jaw 176 while the remainder of theloop 178 havingteeth 182 can slidably engage theclip lock 183.
As shown inFIG. 27, theloop clip 174 can be attached to theloop clip applicator 172 and maintained in an insertable position. Theloop clip 174 and theshaft 36 can be inserted into the patient's chest to bring theloop 178 to a position adjacent the leftatrial appendage 12. Theloop clip 174 can be manipulated to a position where thelower jaw clip 176 is adjacent the base of the leftatrial appendage 12 and theloop 178 extends around the leftatrial appendage 12. Theactuator suture 110 can be attached to anactuator 108, which can include aknob 50 and atorque screw 82, as shown inFIG. 23. Theknob 50 can be turned to traverse the hex head of thetorque screw 82 to bear against theactuator suture 110 in order to pull theslidable end 185 of theloop 178 through theclip lock 183 where theteeth 182 can be engaged by thelower jaw clip 176 to substantially permanently hold theloop 178 in position. Theknob 50 can be turned until theloop 178 is pulled as tight as desired against the tissue of the leftatrial appendage 12 in order to isolate the chamber from the atrium. Alternatively, theactuator suture 110 can be looped outside thehandle 38 to be pulled manually by the operator to lock theloop clip 174 in relation thelower clip jaw 176. Otherexemplary actuators 108 can include a linear trigger grip, a linear slider, etc.
As shown inFIG. 28, theloop clip 174, which is shown in a position for encircling and occluding the left atrial appendage to close thechamber 94, can be disengaged from theloop clip applicator 172 by cutting one end of the retention suture 111 and pulling the retention suture 111 from around theengagement portion 177 and out of the patient's body. As shown inFIG. 28, theloop 178 can be engaged by theteeth 182 to thelower clip jaw 176 to a closed position. Theloop 178 can be disengaged from theloop clip applicator 172 by cutting one end of theactuator suture 110 and pulling theactuator suture 110 through theactuator aperture 180 and out of the patient.
Some exemplary devices disclosed provide a tool designed to place a ring-style left atrial appendage occlusion device. The tool can include a handle with a long neck. An upper and a lower jaw can be attached to the handle with a four-bar assembly on a disital end and aknob 50 and atorque screw 82 on a proximal end. Some exemplary tools can include four separate sutures (2 front and 2 rear) that can loop around a ring and then into the upper and lower jaws. The sutures can be positioned in slots on outside edges of the upper and lower jaws and down into the handle. A retaining suture can be positioned through the lower jaw of a ring into a distal end of the handle, and the loop can be completed outside a proximal end of the tool. The retaining suture can be used to pull and then hold the ring tight against the distal end of the handle. Two holes can be positioned in an end of the lower jaw of the ring. Alignment pins can be inserted into the two holes to help hold and position the ring. After routing through the handle, the retaining suture can be positioned into the hex end of the torque screw and through to the other side where the retaining suture are then tied off.
According to some exemplary methods disclosed, a port can be placed in the patient's chest so that when the ring is placed and opened, the left atrial appendage can be pulled into the opening with a grasper, a vacuum cone, an adhesive tool tip, etc. A neck of the tool can include articulation to aid in placement of the ring. A distal end of the tool can be guided through the port and placed near the left atrial appendage. As the torque screw is turned, the upper and lower jaws open parallel to one another. Continuing to turn the torque screw stretches the ring open. Other methods of actuation can be used to pull the sutures, such as a trigger, slider, etc. When the ring is fully opened, the left atrial appendage can be pulled between the upper and lower jaws until properly located. The torque screw can be turned in the opposite direction to release tension on the sutures and relax the ring around the left atrial appendage. The torque screw can be tightened and relaxed multiple times, if necessary to achieve proper placement. Once the ring is properly positioned, the sutures can be cut (either near the ring or on a proximal end of the tool) to release the ring, and the tool can be retracted. An inside edge of the port can be used to close the upper and lower jaws so the tool can be removed.
Other exemplary devices, useful for understanding the invention, provide a tool designed to place a clip-style left atrial appendage occlusion device. The clip can be a rigid one-piece clip with a snap-in lock on one end. The clip can also include a living hinge that is spring biased open on the other end. However, other exemplary tools can be used with other types of rigid clips, as well as a different hinge or latching mechanism. The tool can include a handle with a long neck. Two separate suture loops can be positioned along the length of the handle inside the neck. A stop on a distal end of the tool can be actuated on a proximal end of the tool. An actuation suture can be positioned through an upper clin jaw of the left atrial appendage clip, then through a lower clin jaw, into a distal end of the handle and complete a loop outside a proximal end of the handle. A port can be created in the patient's chest such that when the clip is positioned near the left atrial appendage, the left atrial appendage can be pulled between the upper and lower clip jaws with a grasper. The neck on the tool can articulate to aid in placement of the clip. The stop can be placed in its forward position to keep the upper clip jaw from latching while pushing it through the port. The clip can spring open after it has passed through the port. The handle can be used to position the clip near the left atrial appendage and the left atrial appendage can be pulled between the upper and lower clip jaws with a grasper. Once the clip is positioned on the left atrial appendage as desired, astop actuation knob 50 can be pulled back to retract the stop. The actuation suture can be pulled (or actuated with a trigger, slide, screw, etc.) until the upper clip jaw snap latches into the lower clip jaw. The left atrial appendage is then occluded. The sutures can be cut and pulled through the handle, which can release the clip. The sutures can be cut with a scalpel, scissors, or other surgical instruments, or the sutures can be cut with a mechanism that is built into the tool itself. The tool can then be removed from the port.
Some exemplary devices, useful for understanding the invention, provide a tool designed to place a loop-clip style left atrial appendage occlusion device. The tool can include a handle with a long neck. The tool can include two separate suture loops that can be positioned through the length of the handle and a shaft. The tool can include aknob 50 and a torque screw on a proximal end of the handle and the shaft. Theloop clip 174 can include a rigid base with a flexible loop that can include one-way teeth molded into it. The loop can wrap around one end of the rigid member and through a slot with a locking snap (like a cable tie). This allows the loop to be pulled in, but not release. The end of the loop can include a hole that a suture can be routed through. The suture can be positioned into the distal end of the placement device, can be positioned through the handle, into the hex end of the torque screw, and tied off on an opposite end. A retaining suture can be positioned through a hole in an end of the loop clip, then into a distal end of the placement device, positioned through the handle, and tied off on a proximal end of the tool. The retaining suture can be used to pull and hold the loop clip tight against a distal end of the handle. An alignment boss on an end of the handle can be inserted into a matching slot on the loop clip to ensure proper alignment. A port can be created in the patient's chest so that when the loop clip is positioned, the left atrial appendage can be pulled between the loop and the base with a grasper. The neck on the placement tool can articulate to aid in placement of the loop clip. The flexible loop can be pushed down to place the loop clip through the port, then once it is through, the loop can return to its original shape. The handle can be used to position the loop clip near the left atrial appendage and the left atrial appendage can be pulled inside the loop with a grasper. Once the loop clip is positioned on the left atrial appendage as desired, turning the torque screw can gradually tighten the loop (a trigger, slide, etc. could also be used to tighten the loop). The torque screw can be turned until the loop is tight enough to occlude flow and remain securely placed. After the loop is tight enough, the actuation suture and the retaining suture can be cut and pulled through the handle. The tool can then be removed from the port.
Some examples disclosed include exemplary devices and methods for occlusion or ligation of an atrial appendage or other tissue. The exemplary method and applicators disclosed herein describe a minimally-invasive approach to ligation of an atrial appendage, specifically, of the left atrial appendage of patients with atrial fibrillation. Some devices disclosed include exemplary methods and apparatus to access the left appendage through a small incision and the use of a delivery tool to apply an occluder to the appendage. The tool can be used to grasp the appendage to help stabilize the appendage to allow for application of the ligation device. The ligation device may be applied and left behind as a permanent implant.
Some examples disclosed include an exemplary device and procedure that can occlude the left atrial appendage from the body of the left atrium - thereby substantially preventing the formation of a clot within the appendage and a subsequent embolism. Some devices disclosed include an exemplary implantable device and applicator for substantially permanently occluding the left atrial appendage. Some examples disclosed include an exemplary device and procedure that is minimally invasive to apply a device as a simple and quick method to deliver therapy to prevent embolic strokes. Some examples disclosed include an exemplary device and procedure that does not require the use of blood-contacting biomaterials. Some examples disclosed include a device and procedure that results in tissue necrosis at the left atrium/left atrial appendage junction that is necessary to help prevent reentry. Some examples disclosed include a device and procedure that places a device to occlude while preserving the tissue of the left atrial appendage for the production of atrial hormones. Some examples disclosed include a device and procedure with a substantially permanently-implanted clamp used for occluding the left atrial appendage. Some examples disclosed include a device and procedure that is applied from the exterior of the heart, which may be accessed by a sternotomy, thorocotomy, minimally invasive, endoscopic or other means. Some examples disclosed include a device and procedure that may be practiced by a number of different embodiments of the clamping mechanism as disclosed herein.
FIG. 30 illustrates adevice 200 for ligation of an atrial appendage. Thedevice 200 can include a ring applicator ordelivery tool 202 and an occlusion member orring 214. Theocclusion ring 214 can be made of a 30A durometer silicone rubber, although other hardnesses of silicone or other materials, such as polyurethane can be used. Thering 214 can be covered with a material such as Dacron® polyester to promote tissue ingrowth and prevent ring slippage after placement. Thering 214 can be generally expandable for placement around the atrial appendage. Thedelivery tool 202 can be used to expand thering 214. Thedelivery tool 202 can include ashaft 220 and ahandle 230 coupled toshaft 220. Thedelivery tool 202 can be sized for reaching an atrial appendage through an opening in the patient's chest, for example, through a sternotomy or thoracotomy. Thedelivery tool 202 can include a tissue-graspingmember 210. The tissue-graspingmember 110 can be a mechanical grasping member, for example, hooks, barbs, or graspers, or it can be a suction grasping member (as shown inFIG. 30), or it can be an adhesive. Thedelivery tool 202 can include one or more suction lumens fluidly coupled tosuction grasping member 210. The suction lumens can pass through theshaft 220 and/or handle 230, or portions thereof. Thesuction grasping member 210 can be coupled to a suction source. The tissue-graspingmember 210 can be used to grasp the atrial appendage and pull it throughring 214. The tissue-graspingmember 210 can be moved distally and/or proximally relative toshaft 220. Thedelivery tool 202 can include a mechanism for controllably moving the tissue-graspingmember 210. This mechanism can be located at or near thehandle 230.
Thedelivery tool 202 can include aring spreader 240 having ring-expandingmembers 242 used to hold and expand thering 214. Thering spreader 240 can be coupled to a distal end ofshaft 220. Thedelivery tool 202 can include multiple ring-expandingmembers 242, for example, four, as shown inFIG. 30. Alternatively, thedelivery tool 202 can include three or five expandingmembers 242, for example. Thering 214 can be releasably coupled or attached to a distal end of ring-expandingmembers 242, for example, via one ormore sutures 250. Thesutures 250 can loop around thering 214. The ends of thesutures 250 can pass through one or more lumens within thering expanding members 242, theshaft 220, and thehandle 230. One or more portions of thesutures 250 can be exposed at or near distal or proximal ends of thehandle 230. For example, portions ofsutures 250 can be exposed at asuture cutting location 270. Exposure of thesutures 250 at or near thehandle 230 can enable the release of thering 214 from thedelivery tool 202 remotely. Thesutures 250 can be cut and removed, thus releasing thering 214 from thedelivery tool 202. Cutting thesutures 250 can release thering 214 from the ring-expandingmembers 242. Thedelivery tool 202 can include one or more suture cutting members.
As shown inFIG. 30, thehandle 230 can include aring expansion mechanism 260 used to control the expansion of thering 214. Thering expansion mechanism 260 can be coupled to the ring-expandingmembers 242. Thering expansion mechanism 260 can control movement of thering expanding members 242 from a closed or collapsed configuration to an open or expanded configuration, as shown inFIG. 30. Thering expansion mechanism 260 can include a screw mechanism. Thering expansion mechanism 260 can control movement of the ring-expandingmembers 242 into and out ofshaft 220. The pulling of the ring-expandingmembers 242 into theshaft 220 can collapse the ring-expandingmembers 242 into a closed configuration. The pushing of the ring-expandingmembers 242 out of theshaft 220 can expand the ring-expandingmembers 242 into an open configuration. The ring-expandingmembers 242 can be spring biased into an open expanded configuration. Thering expansion mechanism 260 can be located at or near distal or proximal ends of thehandle 230. Thering expansion mechanism 260 can include one ormore knobs 261 and one or more threadedmembers 262, as shown inFIG. 30.
As shown inFIG. 31, thedelivery tool 202 can be placed around the leftatrial appendage 12 of aheart 20.FIG. 31 schematically illustrates the structure of the left andright atria 11 and 21, respectively, as viewed from a posterior aspect, including the bases of thepulmonary veins 23 and the bases of the superior vena cava andinferior vena cava 25 and 27, respectively, which enter theright atrium 21.FIG. 31 also schematically illustrates the left and rightatrial appendages 12 and 22, respectively.
FIGS. 32 and 33 schematically illustrate an outline of theleft atrium 11 of theheart 20 with the leftatrial appendage 12 protruding therefrom. Thering 214 can be placed in a position to surround the leftatrial appendage 12 adjacent to the leftatrial appendage base 18 where the leftatrial appendage 12 is attached to theheart 20. Thering 214 can be made of an elastic material to allow it to be stretched into an open or expanded position, as shown inFIG. 32. Thering 214 can be allowed to return to a closed or collapsed position, as shown inFIG. 33, in order to bear against the tissue of the leftatrial appendage 12 and to substantially close off any interior connection between theleft atrium 11 and the leftatrial appendage 12.
As shown inFIG. 32, thering 214 can be attached to a patient'sheart 20 to isolate the leftatrial appendage 12 from theleft atrium 11.Multiple rings 214 can be placed successively more and more proximal to thebase 18 of the leftatrial appendage 12. The elastic material of thering 214 can be any biocompatible material, thereby allowing thering 214 to be left on theheart 20 permanently. Thering 214 can have different relative sizes to accommodate different anatomy requirements of the patient. Thering 214 can be manufactured with radio opaque qualities, such as micro-sized glass beads molded into the elastic material. Alternatively, thering 214 can be made radio opaque by the addition of glass or metallic fibers in the elastic material. Thering 214 can be entirely biocompatible to allow for use for the life of the patient. Thering 214 can have size variations in its inner diameter along a contact surface.
Surgical access to the left atrial appendage can be through a left-sided thoracotomy or laproscopic port incision. The delivery tool and attached collapsed ring can be inserted through the left thoracotomy access. The ring can then be expanded. The left atrial appendage can be grasped and drawn or pulled through the expanded ring. The ring can be positioned toward the base of the left atrial appendage and released from the delivery tool. The delivery tool can then be removed from the patient, and the incision can be closed. Various imaging methods can be employed before, during, and after the tissue occlusion procedure. For example, contrast fluoroscopy, trans-thoracic ultrasound, and/or trans-esophageal echo (TEE) can be employed. Other surgical approaches are possible including sub-xyphoid.
As shown inFIG. 34, some exemplary devices provide anadjustable band occluder 314. Theadjustable band occluder 314 can include aband 316, aloop 318, and anadjustment mechanism 320. The size of theloop 318 can be varied by moving theadjustment mechanism 320 along the length of theband 316.
Some exemplary devices of the present disclosure address a number of problems, such as surgical access to the endocardial surfaces of the atrial chambers of a beating heart and permanent closure of the atrial appendage volume. These problems have been addressed by others using various methods and devices, such as percutaneous catheters. The right atrium may be accessed via transvenous catheters placed through a femoral vein in the groin, as well as through superior veins such as the subclavian, brachiocephalic, or jugular veins. The left atrium is more difficult to reach transvenously, requiring first, right atrial access followed by a transseptal puncture through the fosa ovalis of the inter-atrial septum into the left atrium. With these transvenous methods, only relatively small diameter catheters can be passed through the vasculature. In addition, these devices must be navigated using fluoroscopic guidance or some form of electronic navigation.
Positioning and placement of the therapeutic elements of such catheters can be a challenge, because the movement is controlled remotely from the point of venous access. From point of entry into the body to the therapeutic end of the catheter, the distance may be 70-110 cm through a difficult path. In cases where tissue contact force is critical, this can be a significant problem. Stability of the catheter tip is an issue in a beating heart compared to firm control possible with much shorter and more rigid surgical implements. A number of commercially-available catheters may be able to be positioned in most areas of the atria, but only one catheter-based device has been developed to permanently close off the left atrial appendage following a procedure. This device, known as PLAATO (percutaneous left atrial appendage total occlusion) must be carefully sized to allow positioning within the left atrial appendage such that it is retained in position distal to the ostium with the left atrial chamber. This presents a significant risk that the device may be released into the atrium and pass into the left ventricle and become entangled in the chordae tendinae supporting the mitral valve or become lodged in the left ventricular outflow tract or aorta. The risks of such a procedure were documented in an abstract by Fischer at the 2005 meeting of the American College of Cardiology -Evelyn Fischer, et al., "Left Atrial Appendage Occlusion to Prevent Stroke in Suboptimal Warfarin Candidates: Current Results of the European Multicenter Registry Trial," American College of Cardiology, Abstract presented at 2005 National Meeting.
The atria may be accessed through sternotomy, thoracotomy, intercostals ports, or under the sub-xiphoid process. Access to the atria is important for treatment of atrial fibrillation (AF), atrial-septal-defects (ASD's), patent foramen ovalis (PFO), and mitral or tricuspid valve disease. Also of importance is the elimination of the left atrial appendage volume at the end of the procedure in order to reduce stroke risk. Surgical removal and closure of the left atrial appendate has been accomplished by using a surgical stapler/ligation device or by suturing the appendage closed followed by surgical excision of the distal appendage. This is not without risks as noted by Krum et al. - David Krum, David L. Olson, Daniel Bloomgarden, Jasbir Sra, "Visualization of Remnants of the Left Atrial Appendage following Epicardial Surgical Removal," Heart Rhythm (2004) 1, 249. Such surgical removal may result in an incomplete reduction of the left atrial appendage and allow a volume to remain unclosed.
Regarding the relationship between the left atrial appendage and stroke risk, Blackshear et al. stated that left atrial appendage obliteration "is a routine part of modern 'curative' operations for nonrheumatic atrial fibrillation, such as the maze and corridor procedures."Joseph L. Blackshear, MD, John A. Odell, FRCS(Ed), "Appendage Obliteration to Reduce Stroke in Cardiac Surgical Patients with Atrial Fibrillation," Ann. Thorac. Surg., 1996; 61:755-759. To assess the potential of left atrial appendage obliteration to prevent stroke in nonrheumatic atrial fibrillation patients, they reviewed previous reports that identified the etiology of atrial fibrillation and evaluated the presence and location of left atrial thrombus by transesophageal echocardiography, autopsy, or operation.
They reviewed the results of twenty-three separate studies and found that 446 of 3,504 (13%) rheumatic atrial fibrillation patients, and 222 of 1,288 (17%) nonrheumatic atrial fibrillation patients had a documented left atrial thrombus. Anticoagulation status was variable and not controlled for. Thrombi were localized to, or were present in the left atrial appendage and extended into the left atrial cavity in 254 of 446 (57%) of patients with rheumatic atrial fibrillation. In contrast, 201 of 222 (91%) of nonrheumatic atrial fibrillation-related left atrial thrombi were isolated to, or originated in the left atrial appendage (p < 0.0001). Their data suggested that left atrial appendage obliteration is a strategy of potential value for stroke prophylaxis in nonrheumatic atrial fibrillation. A device was developed that allows percutaneous left atrial appendage transcatheter occlusion (PLAATO) via transseptal catheterization. Initial studies in dogs demonstrated the ability of the device to seal the left atrial appendage. Sievert et al. reported their initial experience with PLAATO in a human clinical trial involving 15 patients.Horst Sievert, MD et al, "Percutaneous Left Atrial Appendage Transcatheter Occlusion to Prevent Stroke in High-Risk Patients with Atrial Fibrillation," Circulation, 2002, 105:1887.
PLAATO was purported to be a less invasive, percutaneous approach to closing the left atrial appendage. Previous animal studies of the device with follow-up of up to 1 year have demonstrated occlusion of the left atrial appendage with complete healing, absence of erosions, new thrombus formation on the device, or interference with atrial function.
In the initial cohort of 15 patients, occlusion of the left atrial appendage was successful in all, as proven by left atrial angiography. There were no complications associated with the device, either acutely during the implantation procedure or during follow-up. The only complication during the study was hemopericardium in the first patient attempted, which was not device-related. It resulted from left atrial appendage access, and should be easily avoided with increased experience. The procedure was successful in a second attempt in that patient.
All patients did well in follow-up. One theoretical concern is the development of new thrombi on the implant. However, the use of ePTFE on the implant surface should result in relatively benign healing. Histological examination in dogs undergoing PLAATO reveal partial endothelialization at 1 month, which is complete by 2 to 3 months. In these 15 patients, transesophageal echo (TEE) at 1 month showed the surface to be completely smooth and free of mobile thrombi.FIG. 35 illustrates a deployed PLAATO device. Fluoroscopic images of non-occluded left atrial appendage, deployment of the PLAATO device, and left atrial appendage post-deployment can be taken.
A larger cohort of patients was included in the European PLAATO Registry Trial by Fischer, et al. a study that was finished in January 2003 that examined the safety and feasibility of this procedure. This study described the experience of 92 patients. Inclusion criteria were atrial fibrillation (AF) with inability to take Warfarin®, prior cerebral ischemia and/or two clinical risk factors for stroke. After implantation of the PLAATO occluder, the patients were followed with X-ray, TEE and NIH stroke scale in regular intervals. Of the 92 patients, 67% were male with a mean age of 70 ± 9 years. All candidates were successfully implanted. The mean procedure time was 76± 36 minutes and the mean left atrial appendage orifice diameter was 20 ± 3 mm. During follow up, one patient died of a bronchial carcinoma diagnosed 3 months before the one year follow up. One patient sustained a stroke six months post implant. Thus, the yearly incidence of stroke after implantation is 1.9%. With this small number of patients, the estimated risk reduction was 55%.
Of concern, in three patients, a thrombus on the occluder was found prior to hospital discharge (2) and one month after the procedure (1). All thrombi were resolved without sequelae. One device was chosen too small and embolized into the aorta after its release. It was snared with a catheter and was retrieved successfully. Another device was implanted successfully in the very same procedure.
To summarize this group's experience with the PLAATO device, the incidence of stroke in high-risk patients may decrease after implantation of the device. Considerable risks exist with this procedure, including errant transseptal puncture resulting in aortic dissection or atrial free wall perforation resulting in tamponade, embolization of the PLAATO device resulting in device entanglement in cardiac structures, along with thrombus formation on the occluder surface that could lead to emboli production and stroke. In addition, the chronic nature of this implant must be considered. Constant flexture of the nitinol wire structure may lead to long term fatigue and potential fracture and perforation of cardiac or adjoining tissues.
The group of Odell et al, hypothesized that if the atrial appendage could be safely obliterated, then the incidence of embolic stroke may be lessened. John A. Odell, et al., "Thoracoscopic Obliteration of the Left Atrial Appendage: Potential for Stroke Reduction," Ann. Thorac. Surg., 1996, 61:565-569. If the appendage can be obliterated using a thoracoscopic technique, a procedure of lesser magnitude than thoracotomy, then it may offer an alternative form of management for patients ineligible for Warfarin® therapy. To determine the feasibility of atrial appendage obliteration done using the thoracoscope, they performed the procedure in mongrel dogs and in human cadavers.
Transesophageal echocardiography with emphasis on visualization of the left atrial appendage was performed pre-, intra-, and postoperatively. In five dogs, the atrial appendage was obliterated with staples, and in five the appendage was obliterated with an endoloop of 0 Vicryl suture material. Three ports were made - one in approximately the seventh interspace approximately 5 cm from the midsternum (port 1), a second inserted anteriorly in the fourth interspace (port 2), and a third more posteriorly in the fourth interspace (port 3). Carbon dioxide was instilled to a pressure of 4 to 10 mm to collapse the lung. In all animals, the pericardium was opened anterior and parallel to the phrenic nerve.Gordon N. Olinger, MD, "Carbon dioxide displacement of left heart chambers," J. Thorac. Cardiovasc. Surg., 1995, 109:187-188.
Through the first port, the camera was inserted; through the second port, the pericardium was grasped with an instrument; and, using scissors inserted through the third port, the pericardium was opened. The technique then varied depending upon whether the appendage was obliterated with staples or with the endoloop. In those having the appendage stapled, the camera was withdrawn fromport 1 and inserted in port 3. Throughport 1, a 35 endo GIA stapler (Ethicon Endosurgery, Cincinnati, OH) with the knife blade removed was inserted, positioned across the base of the atrial appendage, and fired. In dogs having the appendage obliterated with the endoloop (Ethicon), the camera position was not changed. The endoloop was introduced through port 3 and the appendage was grasped through the loop of the suture. The loop was positioned across the base of the appendage and then tightened.
At 11 weeks, the dogs were again anesthetized with sodium pentobarbital (30 mg/kg intravenously) and a midline sternotomy was made. The heart was examined using epicardial echocardiography. The dogs were euthanized, the hearts were removed, and the left atrium was inspected.
The procedure also was attempted in eight human cadavers. In the cadavers, three ports were used for access. The most appropriate sites appeared to be the second interspace anteriorly in the midclavicular line (for grasping the pericardium and the atrial appendage), the sixth interspace in the midclavicular line (for the camera or stapling instrument), and the fifth interspace in the anterior axillary line (usually for the scissors to open the pericardium, but also for the camera or for the stapling instrument). The procedure as performed in the dog and human experiments is illustrated inFIGS. 36A-E.
The group of DiSesa investigated the use of an automatic surgical stapler for ligation of the atrial appendage in sheep, and then applied this technique in patients.V. J. DiSesa, S. Tam and L. H. Cohn, "Ligation of the Left Atrial Appendage using an Automatic Surgical Stapler," The Annals of Thoracic Surgery, Vol. 46, 652-653. Fourteen adult sheep underwent ligation of the left atrial appendage using a surgical stapler with a rotating head and either absorbable or stainless steel staples. In four sheep, killed after two hours, no hemorrhage or intra-atrial thrombus was observed acutely. Ten sheep were allowed to recover for 90 to 100 days, twice the expected absorption time of absorbable staples. There was complete obliteration of the left atrial appendage without evidence of intra-atrial thrombus or staple migration. The absorbable staples were completely reabsorbed. They subsequently used this technique in five patients undergoing mitral valve procedures. There were no complications, and adequate obliteration of the atrial appendage was achieved. Other reports indicate that staples may require the use of reinforcement strips to prevent bleeding and tissue tearing.
Considering the simple surgical ligation methods, the group of Katz, et al. studied the incidence of incomplete ligation of the left atrial appendage during mitral valve surgery.Edward S. Katz MD, FACC, Theofanis Tsiamtsiouris MD, Robert M. Applebaum MD, FACC, Arthur Schwartzbard MD, FACC, Paul A. Tunick MD, FACC and Itzhak Kronzon MD, FACC, "Surgical Left Atrial Appendage Ligation is Frequently Incomplete: A Transesophageal Echocardiographic Study," Journal of the American College of Cardiology,. Using transesophageal Doppler echocardiography, they studied 50 patients who underwent mitral valve surgery and ligation of the left atrial appendage. Incomplete left atrial appendage ligation was detected in 18 of 50 (36%) patients. This study demonstrated that surgical left atrial appendage ligation is frequently incomplete. Residual communication between the incompletely ligated appendage and the left atrial body may produce a milieu of stagnant blood flow within the appendage and be a potential mechanism for embolic events. Ligation of the left atrial appendage is frequently performed during mitral valve surgery to eliminate a potential source of emboli. However, the success of completely excluding the left atrial appendage from the circulation had not previously been systematically addressed. Transesophageal echocardiography offers unique visualization of the appendage in the beating heart and can evaluate the integrity of the surgical ligation. Usually, when the left atrial appendage is ligated, its cavity is obliterated with clot (since no flow enters the cavity) and cannot be seen during echocardiography. This appearance was the same whether the patient was studied in the operating room or months after the surgery. When the appendage is incompletely ligated, not only can the appendage cavity be visualized but flow can be seen within the appendage, as well as through an opening in the ligation site.
The group discovered that 36% of the time the left atrial appendage was found to be incompletely ligated after attempts at excluding it from the left atrial body. Factors, such as an enlarged left atrium or significant mitral regurgitation, which may be thought to increase left atrial tension and pressure (perhaps predisposing to incomplete ligation or dehiscence of sutures), did not appear to correlate with this finding. They also did not observe a correlation between appendage size and the incidence of incomplete ligation. In addition, the surgical procedure (mitral repair or replacement) and operative approach (traditional sternotomy or minimally invasive approach) did not change the incidence of incomplete ligation. It is possible, however, that the sample size in this report may have been too small to exclude a significant effect of these variables on the development of incomplete left atrial ligation.
Incomplete left atrial appendage ligation was as commonly seen in the operating room, evaluating the patient by transesophageal echocardiography immediately after terminating cardiopulmonary bypass, as it was seen in the laboratory evaluating patients referred for transesophageal echocardiography at various times after the surgery. This suggested that incomplete left atrial appendage ligation is not a degenerative process with suture dehiscence over time, but rather is present immediately after the initial surgery. Incomplete ligation may be secondary to several surgical factors. First, the running sutures used may not start and end exactly at the most distal edges of the atrial appendage, which may not be recognized with the appendage empty and unstretched while on cardiopulmonary bypass during surgery. In addition, caution must be taken during appendage ligation to avoid deep suture bites, which may involve the left circumflex coronary artery or its branches that may course in the area. This meticulous care may lead to shallower suture bites that may dehisce when the LA is once again filled and stretched after cardiopulmonary bypass. Both of these mechanisms may play a role, as in many cases flow was detected both at the edge of the appendage orifice (apparently around the end of the suturing line) and through an area at the midpoint of the appendage orifice (through the suture line). One group reported six cases of incomplete left atrial appendage ligation when a purse string suture was used to accomplish the ligation, a technique different from that used by surgeons. The actual incidence, however, of incomplete left atrial appendage ligation using their technique was not addressed.
The clinical significance of an incompletely ligated left atrial appendage has never been studied. Theoretically, creating a small communication between the LA and left atrial appendage may produce stagnation of low velocity blood flow within the atrial appendage. The appendage would then be a model for thrombus formation and continue to serve as a potential source of embolization since a port of entry into the systemic circulation still exists. Although the numbers in this study were small, several observations support this theory. First, spontaneous echo contrast (a marker for stagnant blood flow and a precursor of thrombus formation) was seen within the appendage in half of the patients with incomplete ligation. Second, and perhaps more importantly, in two-thirds of patients with spontaneous echo contrast within the incompletely ligated appendage, the contrast was actually denser within the appendage than within the left atrial body, suggesting a more stagnant and thrombogenic milieu. In two patients, frank thrombus was seen within the incompletely ligated appendage.
The ultimate question, however, is whether patients with incompletely ligated left atrial appendages will have a higher incidence of thromboembolic events. In the Katz study, four patients with incompletely ligated appendages had such events (one patient with Starr-Edwards prosthesis, two with St. Jude prosthesis and one patient status after mitral repair). This is quite a high number considering that only eight patients with incomplete ligation had any potential for long term follow-up (the other ten patients with incomplete ligation were discovered in the operating room). However, one cannot exclude other etiologies for embolization (as mechanical prostheses or atrial fibrillation) and referral bias still clouds this issue. Certainly, conventional ligation methods must be questioned in light of the findings of this study.
A number of devices for occlusion of ASD's have been investigated.Melhem J. A. Sharafuddin, MD; Xiaoping Gu, MD; Jack L. Titus, MD, PhD; Myra Urness, BS; J. J. Cervera-Ceballos, MD; Kurt Amplatz, MD, "Preliminary Results With a New Self-Expanding Nitinol Prosthesis in a Swine Model Transvenous Closure of Secundum Atrial Septal Defects," Circulation, 1997, 95:2162-2168. Most of these concepts involve percutaneous delivery from femoral vein access. Varying levels of success have been achieved. Device dislodgment can occur if the size of the defect greatly exceeds the waist diameter of the device or approaches the diameter of the retention buttons. On the other hand, placement of a disproportionately large device may result in mushrooming of the retention buttons and weakening of the cross-clamping forces against the septal rim, which increases the risk of blood flow behind the discs and may result in incomplete endothelialization. In addition, follow-up studies of a clamshell occlusion device reported a delayed rate of metal fatigue fractures of one or more arms of about 30%. The Amplatzer device is shown inFIGS. 37A-E.
A small introduction system, simple and reliable placement technique, and favorable initial experimental success may provide promising potential of such a device for the percutaneous closure of secundum ASDs in all age groups. Heparinization is advocated in clinical use to lower the risk of catastrophic systemic embolization.
ASD device thrombosis is likely to be similar to thrombosis to be expected on left atrial appendage closure devices. This makes the study by Krumsdorf et al, on the incidence, morphology, and clinical course of thrombus formation after catheter closure of ASD closure devices of interest regarding devices such as PLAATO.Krumsdorf U, Ostermayer S, Billinger K, Trepels T, Zadan E, Horvath K, Sievert H, "Incidence and Clinical Course of Thrombus Formation on Atrial Septal Defect and Patient Foramen Ovale Closure Devices in 1,000 Consecutive Patients," J. Am. Coll. Cardio., Jan. 21, 2004. 43(2):302-9.
A total of 1,000 consecutive patients were investigated after patent foramen ovale (PFO) (n = 593) or atrial septal defect (ASD) (n = 407) closure. Transesophageal echocardiography (TEE) was scheduled after four weeks and six months. Additional TEEs were performed as clinically indicated. Thrombus formation in the left atrium (n = 11), right atrium (n = 6), or both (n = 3) was found in 5 of the 407 (1.2%) ASD patients and in 15 of the 593 (2.5%) PFO patients (p = NS). The thrombus was diagnosed in 14 of 20 patients after four weeks and in 6 of 20 patients later on. The incidence was: 7.1% in the CardioSEAL device (NMT Medical, Boston, Massachusetts); 5.7% in the StarFLEX device (NMT Medical); 6.6% in the PFO-Star device (Applied Biometrics Inc., Burnsville, Minnesota); 3.6% in the ASDOS device (Dr. Ing, Osypka Corp., Grenzach-Wyhlen, Germany); 0.8% in the Helex device (W.L. Gore and Associates, Flagstaff, Arizona); and 0% in the Amplatzer device (AGA Medical Corp., Golden Valley, Minnesota). The difference between the Amplatzer device on one hand and the CardioSEAL device, the StarFLEX device, and the PFO-Star device on the other hand was significant (p < 0.05). For a device such as PLAATO, specifically designed to reduce or eliminate thromboembolic events coming from the region of the implant, occurrence of thrombus on ASD devices is a concern.
A method and apparatus for thoracoscopic intracardiac procedures was described United States Patent Number6,401,720, entitled "Method and Apparatus for Thoracoscopic Intracardiac Procedures," Stevens, John H.; Palo Alto, CA 94303, Reitz, Bruce A.; Stanford, CA 94305, Roth, Alex T.; Redwood City, CA 94061, Peters, William S.; Woodside, CA 94062, Gifford, Hanson S.; Woodside, CA 94062 . They described devices, systems, and methods provided for accessing the interior of the heart and performing procedures therein while the heart is beating. In one example, a tubular access device having an inner lumen is provided for positioning through a penetration in a muscular wall of the heart, the access device having a means for sealing within the penetration to inhibit leakage of blood through the penetration. The sealing means may comprise a balloon or flange on the access device, or a suture placed in the heart wall to gather the heart tissue against the access device. An obturator is removably positionable in the inner lumen of the access device, the obturator having a cutting means at its distal end for penetrating the muscular wall of the heart. The access device is preferably positioned through an intercostal space and through the muscular wall of the heart. Elongated instruments may be introduced through the tubular access device into an interior chamber of the heart to perform procedures, such as septal defect repair and electrophysiological mapping and ablation. A method of septal defect repair includes positioning a tubular access device percutaneously through an intercostal space and through a penetration in a muscular wall of the heart, passing one or more instruments through an inner lumen of the tubular access device into an interior chamber of the heart, and using the instruments to close the septal defect. Devices and methods for closing the septal defect with either sutures or with patch-type devices are disclosed. While this concept allows access to the heart chambers, it does not provide for a simple means of incisional closure.
Some disclosed exemplary devices may provide any one or more of the following advantages: a single point of access for surgical treatment of atrial fibrillation; fewer inter-costal access ports may be needed for treating atrial fibrillation, as opposed to existing minimally-invasive methods; blunt dissection of cardiac tissue is generally not required; pericardium is left substantially intact, except for a small incision; access to the heart for delivery of therapies for various disease states; a single device can provide surgical access to the heart chambers, as well as providing a means of closing the point of access at the end of the procedure; and the left atrial appendage can be ligated and/or eliminated at the close of the procedure with little or no risk of tearing. The left atrial appendage can be eliminated at the close of the procedure such that a residual remaining volume which could lead to strokes is avoided.
Some examples disclosed provide a device that can provide access to the interior of the heart chambers. The device can allow for single point access to treat atrial fibrillation, atrial-septal defects, patent foramen ovalis, and valvular disease, as well as other arrhythmias. Some exemplary devices can be used to access the ventricles from the access achieved through either appendage. Ventricular septal defects can be addressed. The device can be applied to other body structures, such as the stomach where a portion of the stomach wall could be ligated by the elastic band and excluded. This may be suitable as a treatment for obesity.
Some examples disclosed provide exemplary methods and devices to allow entry into the atria of a beating heart to perform delivery of therapy to the structures within the heart and endocardial surfaces and valves associated with the heart chambers. Upon removal of the device from the appendage, a permanent closure and elimination of the appendage volume can be affected. More specifically, the entry points can be located in the left and right atrial appendages. Of these, the left atrial appendage may be most appropriate, because closure and elimination of this appendage following a procedure has become a standard surgical practice performed by many surgeons.
According to exemplary methods disclosed pre-procedure includes placement of one or two chest wall access ports for visualization and placement. The lung can be deflated and a small opening in the pericardium can be made adjacent to the left atrial appendage.FIG. 38 schematically illustrates the relative locations of structures of the heart and chest of interest. More specifically, the left atrial appendage is shown in a stretched state without the pericardium in place. The heart structures noted onFIG. 38 include the following: SVC - superior vena cava, IVC - inferior vena cava, TV - tricuspid valve, FO - fossa ovalis, MV - mitral valve, PV - pulmonary vein, and left atrial appendage - left atrial appendage.FIGS. 39-68 illustrate exemplary ices and methods of using the devices. A device 400 can include anelastic cinch ring 410,ring expansion arms 412, and aportal tube assembly 414. The ring expansion or cinchring support arms 412 can include three or four arms. The device 400 can be positioned through achest port 416 in a portion of thechest wall 418. The device 400 can be passed through achest port 416 placed between the ribs. The anatomical drawings ofFIGS. 39-57 have been simplified to show only the left atrial appendage and the chest wall.
FIG. 39 illustrates theelastic cinch ring 410 in a contracted state.FIG. 40 illustrates the device 400 being advanced toward the left atrial appendage.FIG. 41 illustrates a suction cup orBabcock grasper probe 420 being advanced through theportal tube assembly 414.
FIG. 42 illustrates the suction cup orBabcock grasper probe 420 being attached to an end of the left atrial appendage. Any suitable type of grasper, vacuum device, adhesive, cyrogenic device, or nanotechnology device can be used to grasp and pull the left atrial appendage.FIG. 43 illustrates thesupport arms 412 being expanded and the left atrial appendage being pulled toward theportal tube assembly 414.FIG. 44 illustrates thecinch ring 410 being advanced over the left atrial appendage.FIG. 45 illustrates thecinch ring 410 being positioned over the mid to proximal left atrial appendage.
FIG. 46 illustrates thecinch ring 410 being allowed to contract over left atrial appendage and occlude alumen 422 of the left atrial appendage.FIG. 47 illustrates the suction cup orBabcock grasper probe 420 removed fromportal tube assembly 414.FIG. 48 illustrates a dilator/sheath assembly 424 including adilator 426 and asheath 428 being advanced through theportal tube assembly 414. In some exemplary circumstances, prior to puncturing into the atrial appendage, the thoracic cavity can be inflated with carbon dioxide gas. Carbon dioxide inflation of the pericardial space can be used to lessen the prevalence and consequences of air embolism, can help limit the chances of air introduction, and can help limit bleeding.FIG. 49 illustrates a needle orsharp wire 430 being advanced through a lumen of thedilator 426 to puncture into the leftatrial appendage lumen 422.
FIG. 50 illustrates thedilator 426 being advanced into thelumen 422 of the left atrial appendage and theneedle 430 retracted.FIG. 50 illustrates thesheath 428 being advanced over thedilator 426 into the leftatrial appendage lumen 422.FIG. 51 illustrates the left atrial appendage being filled with heparinized saline, as blood and air are removed. As shown inFIG. 52, the leftatrial appendage lumen 422 can be aspirated ofblood 432 and flushed with heparinized saline using asyringe 434 to prevent thrombus formation. As shown inFIG. 53, the leftatrial appendage lumen 422 can be filled with heparinized saline as blood and air are removed. However, in some exemplary circumstances, it may be desirable to allow blood to form a thrombus in the remaining left atrial appendage volume to promote healing and absorption of the closed-off portion of the left atrial appendage by surrounding tissue.
As shown inFIG. 54, thedilator 426 can be advanced past thecinch ring 410 and into the left atrium. As shown inFIG. 55, thesheath 428 can be advanced over thedilator 426 past thecinch ring 410 and into the left atrium. As shown inFIG. 56, thedilator 426 can be removed. A hemostasis valve (not shown) can be positioned on a proximal end of the sheath. As shown inFIG. 57, therapeutic implements can be advanced into the left atrium for the treatment of various conditions.
FIG. 58 illustrates an exemplaryballoon ablation device 436 positioned at the right inferior pulmonary vein ostium. The use of a cryogenic or high-intensity focused ultrasound balloon ablation device can be used.FIG. 59 illustrates an exemplaryballoon ablation device 436 positioned at the left superior pulmonary vein ostium.
FIG. 60 illustrates an exemplary encirclingablation device 438 approaching the left superior pulmonary vein ostium. Theablation device 438 can use radiofrequency (RF) energy, cryothermy, high-intensity focused ultrasound, microwaves, or any other suitable ablation energy.FIG. 61 illustrates an exemplary encirclingablation device 438 placed around the left superior pulmonary vein ostium.
FIG. 62 illustrates an exemplary left atrial de-bulkingspiral ablation device 440 placed against the posterior left atrium.FIG. 63 illustrates an exemplary high intensity focusedultrasound ablation device 442 that can create a lesion over the left atrial isthmus.FIG. 64 illustrates an exemplary PFO orASD closure device 444 being deployed in the fossa ovalis of the inter-atrial septum.FIG. 65 illustrates an exemplarylinear ablation device 446 forming connecting lesions between the pulmonary veins.
As shown inFIG. 66, at the completion of all the endocardial therapeutic procedures, theelastic cinch ring 410 can be allowed to constrict down around the base of the left atrial appendage. The sutures or other devices holding thecinch ring 410 can be released such that thesupport arms 412 and theportal tube assembly 414 can be pulled away from the heart, while leaving thecinch ring 410 substantially permanently in place at the base of the appendage. As shown inFIG. 67, immediately following the procedure, the left atrial appendage will generally include a volume that is contained by thecinch ring 410. Healing will then occur and the vestige of the left atrial appendage will be absorbed into the atrial wall. As shown inFIG. 68, after approximately 12 weeks, the left atrial appendage is expected to have been absorbed and assimilated by the atrial wall. Thering 410 can remain embedded in the remainingscar 448.
The ring occluders and the clip occluders disclosed herein can be constructed of any one or more of the following materials: silicone rubber, polyurethane, shape-memory polymer or metal, latex, nitrile, butyl, styrene-butadiene, polyacrylate, acrylic, polyisoprene, chloroprene, fluoroelastomers, or other suitable biocompatible elastomeric materials. The ring occluders and the clip occluders disclosed herein can incorporate any one or more of the following features: texturing to aid in mechanical stability (i.e., ridges, bumps, grooves, etc.); fabric such as Polyethyleneterapthalate (i.e., Dacron®), polyester, ePTFE, etc. to promote tissue ingrowth; other types of coatings to promote tissue ingrowth; and controlled-release pharmacological agents to aid in tissue ingrowth, apoptosis, necrosis, revascularization, arrhythmia control, infection control, anti-bacterial, fluid balance (i.e., atrial natritic peptide replacement). The ring occluder cross-sectional shape can be round, square, rectangular, oval, triangular, star-shaped, etc. The ring occluder or clip occluder can be reversibly placed, and its position can be adjusted if necessary. Multiple ring or clip occluders can be placed more and more proximal to the base of the left atrial appendage.
Furthermore, other substitutions, modifications, changes, and omissions may be made in the design, operating conditions, and arrangements of the exemplary embodiments without departing from the scope of the invention as expressed in the appended claims.

Claims

A system for occluding a left atrial appendage (12) of a patient, the system comprising:
a ring occluder (14) that can be positioned around the left atrial appendage (12); and
a ring applicator (34, 202) to position the ring occluder (14, 214) with respect to the left atrial appendage (12),
the ring applicator (34) including a ring spreader (40, 240) with a spreader hinge (46) coupled to an upper spreader jaw (42) and a lower spreader jaw (44),
the ring occluder (14) coupled between the lower spreader jaw (44) and the upper spreader jaw (42),
the spreader hinge (46), including a four-bar assembly (52) for moving the upper spreader jaw (42) and the lower spreader jaw (44) substantially in parallel, moving between an open position in which the ring occluder (14) has a first diameter and a closed position in which the ring occluder (14) has a second diameter, the first diameter being larger than the second diameter.
The system of claim 1 wherein the ring occluder (14) includes at least one of micro-sized glass beads, glass fibers, and metallic fibers.
The system of claim 1 wherein the ring occluder (14) includes a biocompatible, elastomeric material.
The system of claim 1 wherein the ring occluder (14) is covered by a material to promote tissue ingrowth and prevent slippage.
The system of claim 1 wherein the ring applicator (34) includes a jaw actuator (48) that controls the spreader hinge (46).
The system of claim 1 wherein the ring applicator (34) includes a lumen for insertion of a retraction mechanism.
The system of claim 1 wherein the ring applicator (34) includes a lumen for insertion of a viewing device.
The system of claim 5 wherein the jaw actuator (48) includes a knob (50) and a torque screw (82).
The system of claim 5 wherein the jaw actuator (48) includes a handle (38) and a trigger mechanism.
The system of claim 5 wherein at least one suture is coupled to the jaw actuator (48), the spreader hinge (46), and the ring occluder (14).
The system of claim 1 wherein the ring applicator (34) includes a plurality of slots (65, 74) and a plurality of apertures (67, 69, 75, 79) through which a plurality of sutures (66, 68, 70, 72) are positioned.